A structure fire in McKinleyville this evening caused a residence to partially collapse, leaving firefighters unable to search inside the area for any people who may have been inside, Arcata Fire Protection District Battalion Chief Sean Campbell said.

The fire on the 1700 block of Bird Avenue was called in around 6 p.m. The cause is not yet known. Campbell said there was a reported rescue when the fire was called in and when officers first arrived they were not able to do a search for people inside because power lines were down around the building.

"Once they could get in, the crew didn't find anyone in the part of the building that didn't collapse, but part of the building did fall in about 20 minutes into the fire and we haven't been able to search that area yet because it's unsafe," Campbell said. "It could be weeks or months before the investigation is completed."

There were five fire engines at the scene from the Arcata Fire Protection District, Humboldt Bay Fire and the Blue Lake Fire Department and the fire was well-involved when they arrived, Campbell said.

"The down power lines hindered us from entering at first. This could have been a result of the fire, we don't know yet. The wind also added to the challenge," Campbell said. "We fought the fire defensively from the outside. Other neighboring properties were starting to catch fire but it ended up being limited to the one structure."